Wireless-telegraph calling device



April 7, 1925.

w. H. NOTTAGE ET Al.

WIRLESS TELEGRAPH CALLING DEVICE Original Filed DeC- 18., 1920 2 Sheets-,Sheet 1 wua/ntoz W.H.NOTTAGE & T. D. PARKN April 7, 1925. 1,532,336

W. H. NOTTAGE ET AL.

WIRELESS TELEGRAPH CALLING DEVICE original Filed Dc. 18, 1920 2 sheets-sheet 2 Patented Apr. 7, 1925.

UNITED STATES PATENT oFFICE.

WILLIAM HOCKLEY NOTTAG'E, OF uiEIUISIII'IIP, AND THOMAS DIXON PABKIN, 0F GHELM8- FORD, ENGLAND, ASSIGNOBS TO RADIO' CORPORATION OF AMERICA, A CORPORA- TION F DELAWARE.

WIRELESS-TELEGRAPH CALLING DEVICE.

Original application led December 18, 1920, Serial No'. 431,599. Patent No. 1,452,925, dated April 24, 1923. Divided and this application lecll February 23, 1923. Serial No. 620,806.

To all whom z't may comer/n.'

Be it known that we, WILLIAM Hooxnnr NoT'rAGE, of Mawbyns Kingsen Avenue, Ruislip, England, and THOMAS DIXON PAR- l K1N, of Ransford Lodge, Chelmsford, England, Britishrsubjects, have invented new and useful Improvements in Wireless-Telegraph Calling Devices (division of my prior application, Serial No. 431,599, filed December 18, 1920, for wireless-telegraph calling device, now Patent -No. 1,452,925,

atented April 24, 1923), of which the folowing is a specification accompanied by drawings.

This invention relates to wireless telegraphic callingdevices of the type in which impulses are transmitted at regular intervals and are received by a balance wheel relay, or the like, which has a natural oscillation period equal to the interval between successive impulses so that though the relay may be unaffected by ordinary signals, yet when a train of impulses at predetermined intervals is incident upon the receiver the oscillations of the relay are increased by the impulses suiiiciently to enable it tov actuate a bell or other signal or operate in some way an electric circuit for the control of apparatus.

ccording to this invention we' employ for transmitting and receiving the impulses, timing mechanism comprising a spring controlled balance wheel oscillated by an electroma rupte by the oscillations of the wheel. The

preferred arrangement is illustrated by the accompanying drawing, in which Figs. 1 and 2 are, respectively, front and side elevations of our timed transmitter, n

Fig. 3 shows a modiication of ourtimed transmitter,

Figs. 4 and 5 are, respectively, end and front elevations of our oscillation relay, and Figs. 6, 7 and 8 are diagrams of the method of connecting our receiving apparatus.

Figures 1 and 2 show a front and Side elevation (taken from the right of Fig. 1) of an oscillating wheel (hereinafter referred to as a timed.transmitter). A spindle D which can oscillate in fixed bearings E is connected by a spring H to an adjustable' support J and carries the armature B of an et the circuit of which is interelectromagnet A C the poles A of which are arranged on opposite sides lof the spindle D. The armature B supports a ring K of nonmagnetic material in order to'give the movement the required moment of inertia. The spindle D carries also a spring blade F on the end of which is a contact piece adapted as the spindle in its oscillation reaches a certain position to impinge upon a stationary contact G and thus to complete a circuit comprising a battery and the windings G of the lectromagnet A C.

The stationary contact G is so arranged that the pressure between F and G is sufiicient to make a good electrical contact but not to have on the time period a controlling eii'ect at all comparablto the control exerted by the spring H.

Mounted on spindle D is a cam L of insulating material arranged to press together two springs M and N each fitted with contact pieces in the circuit of which is located the apparatus to be controlled.

The cam L is shaped so that the point of the oscillation of the spindle D at whichM and N make contact and the time during which M and N are in contact relative to the period of oscillation of D are adjustable and springs M' and N are arranged so that the' pressure between them and the cam does not have on the timey period of D a controlling effect at all comparable to the control exerted by H.

Alternately the cam L and spring contacts M and N may be omitted as described below in connection with Fig. 3.

rlhe spindle and the parts carried by it are carefullyl balanced so that the gravity may exert no directive force upon the system nov matter what the position of the spindle.

In order that the tension of spring H may readily be adjusted the support J to one end of which H is secured is carried by a worm wheel P which can be tuned about the axis of the spindle D by a worm Q pro- 4 vided with a milled head.

The timed transmitter as described is so arranged that shortening the arc of travel before the potential energy due to the tension of the spring H reaches a value equal to that of the -kinetic energy given by an impulse dueto a current through C of certain strength will shorten the time between successive/contacts. If therefore a smaller current be sent through C the tension of H when the spindle comes to rest will be less and the are of travel will be less and therefore the time period tends to shorten. On the other hand the reduction in the current reduces the control exerted by the magnetic impulses and therefore the time period tends to increase. These two effects therefore tend to counteract one another and hence the intervals between transmitted impulses .are substantially unaffected by wide variations in the current.

To start the timed transmitter a tapping key U may be provided and as shown in Figure 3 connected in parallel with F and G so that A C may be energized by a few taps roughly in synchronism with the time period of the movement. These taps will start the spindle oscillating and the oscillations will then be automatically maintained.

Included in the circuit of contacts M and N is an electromagnet R V, the armature R of which carries a Contact S. Alternatively the contacts M and N may be omitted from the timed transmitter and the coils V of the electromagnet R V connected in series with contacts F and G.

The contact Swill control the wireless telegraph transmitting circuit so as to send out signals at intervals iixed by the period of the timed transmitter and of duration depending on the setting of cam L or alternatively of the time during which F and G remain closed.

For receiving the signals we employ a spicial oscillating relay shown in Figures 4 an 5.

The movement consists vof a Spindle l carrying a spring L and a steel ring a with a non-magnetic bar c xed to it along a diameter for securing the ring to the spindle.

The ring is magnetized with its poles at opposite ends of a diameter; the spindle d carries a light arm j on one end of which is a contact piece f. The period of oscillations of the movement is made equal to the time interval between the impulses sent by the timed transmitter.

The spindle al works in fixed bearings e e and has coils c c arranged so as to surround the ring a which has its poles placed at right angles to the common axis of 0 c.

A contact g is fixed to a light flexible arm g carried on a pillar g2 which is arranged so that g may be raised or lowered and so that contact f impinges on g when the motion of the arm j is sufficient.

These contacts f g are included in a circuit by which an alarm bell may be sounded or other device actuated whenthey close.

The oscillating relay as described may be actuated by the signals from the distant timed transmitter in several ways.

The preferred method illustrated in Figure 6 is to connect the coils c c in series with the anode of a valve M and the anode battery N associated therewith. Any apparatus as a telephone'transformer O used for the ordinary working of the receiver may also be included without detriment to our device which in turn need not be disconnected when it is not in use.

The grid of the valve M is connected to one end of a transformer winding P the other end of which is connected through a resistance R of several hundred megohms to the filament circuit of the valve. The arrangement is such that the incidence of an impulse causes a diminution in the current through the coils and this diminution starts the oscillation of spindle d.

It will be seen that no incident signal however strong can vary the current through the coils to a greater extent than to make it zero and therefore the maximum impulse imparted to the movement is limited so that if the distance between contacts f and g be made sufficient no change in the current through the coils due to ordinary signals can be suflcient to cause the contacts to close the circuit.

As shown in Figure 7 the contacts f g are shunted by an inductance S and capacity T and are connected in series with a battery, an alarm V such as an electric bell and a holding electro-magnet W which has a pair of contacts X Y normally open but closed by the movement of the armature Z of the magnet W so that when once this magnet has been energized the contact through the alarm or other device is maintained.

An alternative method for using the oscillating relay is to include the coils c c in series with a battery and the contacts of an electromagnetic relay of known type. Instead of connecting the coils c c as shown in Fig. 6, the coil of the electromagnetic relay may be connected (as in Fig. 8) in the anode and anode battery circuit of valve M so that whenever the contacts of the relay are closed by a diminution of the current through the coils` an impulse due to a current of definite value is sent through the coils c c no matter what the strength of the signals which actuate contact S.

Having described my invention7 what I claim is: f

1. In radio receiving apparatus the combination of an antenna, a spring controlled balance wheel, and electro-magnetic means controlled by said antenna for causing said balance wheel to oscillate.

2. In radio receiving apparatus the combination of an antenna, a spring controlled balance wheel, an indicator controlled by said balance wheel and means for causing energy received on said antenna to control the oscillations of said balance wheel.

3. In radio receiving apparatus the comllO bination of antenna, a spring controlled i 5 tenna and arranged to control said electromagnetic means.

4. In radio receiving apparatus the com bination of an antenna, a spring controlled balance'wheel, electro-magnetic means for causing said balance wheel to oscillate, an 1o indicator arranged to be energized by said balance wheel when lthe oscillations thereof have attained a predetermined value, and a thermionc Valve for controlling said magnetic'means, said valve being controlled by l5 the energy received on said antenna.

WILLIAM HOCKLEY `NOTTAGE.. THOMAS DIXON PARIHN. 

